Sir Colin Davis, the veteran English conductor, is a great man of Mozart — and of Berlioz, and of Sibelius, and of others. But Wednesday night belonged to Mozart. Sir Colin brought the London Symphony Orchestra — and London Symphony Chorus — to Avery Fisher Hall. The main work on the program was Mozart’s Requiem.

First, however, Sir Colin performed Mozart’s Piano Concerto No. 27 in B flat, K. 595, with Imogen Cooper. Ms. Cooper is an English pianist whose career has been varied: chamber music, lieder accompanying. And K. 595 is Mozart’s last concerto.

As I always say — perhaps to the point of tiresomeness — it’s important to remember that Mozart didn’t intend this concerto to be his last. Neither did he intend the “Jupiter” to be his last symphony. It just worked out that way, alas. Nonetheless, we have a habit of investing these “last” works with extra, valedictory meaning. Probably can’t be helped.

But Mozart was just motoring right along. K. 595, for example, is merely another piano concerto — merely another masterpiece. The man had inexhaustible supplies of them. Opening this concerto, Sir Colin was relaxed, unhurried — mature. But soon the music would become all too relaxed. The first movement was oddly autumnal, and even sleepy. It is marked Allegro. But there wasn’t much allegro about our performers’ approach.

Ms. Cooper proved a mature pianist, matching a mature conductor. She made bold sounds, but not hard or vulgar ones. Indeed, much of her playing was pearly. Her passagework was often crisp and lovely, but sometimes it was stiff. Against stiffness, pianists must be on constant guard.

Ms. Cooper began the second movement, Larghetto, with great purity — astonishing purity, really. And she would continue that way throughout. Again, this movement was slow – maybe a Largo without the “etto.” But it had affection and beauty.

The closing Allegro was — you guessed it — slow. But at least it had the virtue of conforming to the other movements. And Ms. Cooper and Sir Colin seemed convinced of what they were doing. I have a question about the cadenza, however: Why those odd hesitations? They were not particularly musical.

So, this was an unusual performance of Mozart’s last concerto: wise, in a way, but in need of more spine, more sparkle. Just an extra dose of those qualities would have made a decisive difference. After the concerto, an enormous cake was wheeled out, from which Sir Colin cut an honorary slice. Why the cake? In honor of the conductor’s 80th birthday, which occurred last month. Sir Colin is an enviable 80, in multiple ways. On the stage of Avery Fisher Hall, his huge shock of white hair was as bright as anything on Broadway.

A question: Is Mozart’s Requiem better in a church than in a venue like Avery Fisher? (Avery Fisher is a determinedly this-worldly place.) Sure. But a good conductor, and good musicians, can transform just about any venue into the right one. The music, rightly conveyed, alters the atmosphere. And this is what Sir Colin et al. did on Wednesday night. (In truth, Mozart did it too.)

In a review published yesterday, I spoke of Mozart of the “right size.” And Sir Colin’s Mozart is very much like that: not bloated, not thin; not too rich, not too gruelish; balanced and natural. There is a sense of just rightness about Sir Colin’s Mozart, as there is about James Levine’s. One difference: Sir Colin tends to be more easygoing; with Mr. Levine, the fist is just a little tighter.

On this occasion, the Requiem had all the spirituality it must. But Sir Colin never forced the issue; any forcing would have backfired. The music simply breathed as itself.

And we had a fine quartet of solo singers. The soprano Marie Arnet showed an attractive, vibrant voice. Initially, she sang sharp, which is unusual: You almost always hear flat. But she quickly settled into pitch, and, later, her high soft singing was exemplary. But there was something about Ms. Arnet much more important than this: Her singing was honest. And this is indispensable in Mozart, as in other music.

A word to the wise, though: Ms. Arnet has a habit of “nod-conducting,” as I call it, when she sits and listens to the music. She might curtail that. Then again, you might applaud her for being engaged.

The bass, Darren Jeffery, showed a clean, focused, beautiful instrument. Some low notes weren’t quite there, however. The tenor, Andrew Tortise, was intense and pinched — and effective. The mezzo-soprano, Anna Stéphany, sang with elegant solidity.

And the London Symphony Chorus performed with the professionalism for which it has long been known.

In sections such as the Lacrimosa, Sir Colin was precise and respectful without being overly careful — this is part of his Mozartean naturalness. The D major of the Sanctus never sounded more joltingly glorious. And the life — yes, life in a requiem — running through the Benedictus was memorable.

When Colin Davis is on the podium, performing Mozart, I don’t hear conducting. I hear Mozart. On Sunday afternoon, Sir Colin and these forces will perform Haydn’s “Creation.” I imagine we’ll hear Haydn.